Anyone know what I need to get the rear window defroster to work? Never came stock with one just got "new" hard top with option and got the dash switch, but no action or light at the switch. It is simple as a fuse or something?, or do I need to dig a little deeper in the wiring harness, seems I have everything going back to the hard top. (Old Jeep had a factory soft top that had nothing going back minus the rear dome light wiring), but present Jeep came factory with rear wiper and seems all necassary wires are there.

I'd be interested in hearing about this too, I'm troubleshooting a '93 YJ with factory rear defroster, and rear wiper. The rear dome light and windshield wiper work. Were do the rear defroster wires go after leaving the connector on the hard top?

After years of not having my rear defroster work I finally got it working this year. My Jeep had the wiring harness already in it, the only thing it didn't have was the switch. I wired up the switch last year and thought I followed the wiring diagram but it still would not work. This year I decided to check it one more time and I found that the defroster relay was full of water. Once I replaced that, my rear defroster works great except for a few lines that do not heat. In answer to your question, if you pick up a Haynes manaul you can follow the wiring diagram in there. The relay is located under the dash near the fuse box.

Anyone know what I need to get the rear window defroster to work? Never came stock with one just got "new" hard top with option and got the dash switch, but no action or light at the switch. It is simple as a fuse or something?, or do I need to dig a little deeper in the wiring harness, seems I have everything going back to the hard top. (Old Jeep had a factory soft top that had nothing going back minus the rear dome light wiring), but present Jeep came factory with rear wiper and seems all necassary wires are there.

You need to check the tub harness by the door hinge strap/parking brake bracket area on the drivers side of your YJ. It must have a red timer relay socket and red timer relay marked 'TIMER' on it. It will only be in the tub harness if the YJ was ordered from the factory with the hardtop option OR if someone changed out/modifeid the harness there.

The dash harness will have a red switch socket that plugs into the rear defroster switch. All you have to do for the switch is cut out the blank section on the dash plate, plug in the switch, snap it into the dash hole you just made and that is done, BUT, the power for the rear defroster switch comes through the red timer relay I mentioned earlier. I went through this myself. I bought a tub harness from EBAY that had the timer relay in it for about $50.00 I stripped out all the wiring associated with the rear defroster circuit and spliced it into my tub harness. It is the cheapest way trusy me. The toimer relay alone cost about $37.00 then you need the relay socket and all the associated wiring.
Here is a tub harness with the relay in it for sale on EBAY right now: http://cgi.ebay.com/ebaymotors/Jeep-...ayphotohosting

Once you get it working you can fix any broken wires on the glass with a kit from an auto parts store. I did it on mine and it worked fine. Find the location of the break with a meter and then apply the repair stuff. It looks like some kind of glue with powdered copper in it.
Sandy